Mixtures of polycarbonates with siloxane-containing graft polymers

Abstract

The invention relates to thermoplastic polycarbonate molding compositions containing polycarbonates, special siloxane-containing graft polymers and, optionally, lower thermoplasts and/or standard additives and to a process for the production of the polycarbonate molding compositions.

We claim: 
     
       1. Thermoplastic polycarbonate molding compositions containing A. 52 to 94% by weight of one or more polycarbonates and   B. 6 to 48% by weight of one or more particulate graft polymers wherein said graft polymer is prepared by grafting   B.1 20 to 90 parts by weight of a polymer graft overlay of at least one α,β-unsaturated, olefinic monomer onto   B.2 80 to 10 parts by weight of a graft base having a core/shell structure, consisting of a core of (a) an organic, resin-like polymer of at least one olefinicaly unsaturated monomer having a glass temperature (Tg) of >30 ° C. and a shell polymer (shell) of   (b) crosslinked silicone rubber,     the ratio by weight of the core (a) and the shell (b) being from 0.1:99.9 to 90:10, the graft polymer B) having an average particle diameter of from 0.05 to 10 μm and the sum of the parts by weight of B.1 and B. 2  always amounting to 100 parts by weight.   
     
     
       2. Thermoplastic polycarbonate molding composition as claimed in claim 1, characterized in that the core (a) in the graft polymer B) has a glass temperature of >60° C. 
     
     
       3. Thermoplastic polycarbonate molding composition as claimed in claim 1, characterized in that the core a) in the graft polymer B) has a glass temperature of >90° C. 
     
     
       4. Molding composition as claimed in claim 1, containing A) in quantities of 60 to 86% by weight and B) in quantities of 14 to 40% by weight. 
     
     
       5. Molding composition as claimed in claim 1, characterized in that component B) is prepared from 30 to 80 parts by weight B.1 and 70 to 20 parts by weight B.2. 
     
     
       6. Molding compositions as claimed in claim 5 characterized in that component B) is prepared from 40 to 75 parts by weight B.1 and 25 to 55 parts by weight B.2. 
     
     
       7. Molding composition as claimed in claim 1, characterized in that the ratio by weight of the core a) to the shell b) in the graft polymer B) is from 10:90 to 50:50. 
     
     
       8. Molding composition as claimed in claim 1, characterized in that the average particle diameter (d 50 ) is 0.1 μm to 2 μm. 
     
     
       9. Molding composition as claimed in claim 8, characterized in that the average particle diameter (d50) is 0.1 μm to 1 μm. 
     
     
       10. Molding composition as claimed in claim 1, characterized in that they additionally contain stabilizers, pigments, mold release agents, flameproofing agents and/or antistatic agents.